Comparative Study of Intraperitoneal Infiltration of 0.5% Ropivacaine with and without Morphine in Laparoscopic Cholecystectomy for PostOperative Analgesia

Introduction: Patients after laparoscopic cholecystectomy complain more of visceral pain which results from the stretching of intra-abdominal cavity, peritoneal inflammation and phrenic nerve irritation caused by residual carbon dioxide in the peritoneal cavity. Intraperitoneal (IP) local anaesthetics and opioids are gaining popularity for better pain relief in laparoscopic surgeries. The rationale to use the intraperitoneal route is that the peritoneum is exposed to blocking of visceral nociceptive conduction, thereby providing an additional mechanism of analgesia. Methods: All eligible patients were randomly allocated into two groups as Group R (0.5% Ropivacaine group) and Group M (0.5% Ropivacaine plus Morphine group) by using calendar odd and even date method. At the end of surgery, after removal of gallbladder, study drug was instilled onto the gallbladder bed intraperitoneally via port under vision. Group R patients received 20ml of plain 0.5% ropivacaine while Group M received patient’s received18ml of plain 0.5%ropivacaine plus 2ml (3mg) morphine. The main aim of our study was to assess the postoperative duration of analgesia in both the groups with NRS (Numerical Rating Scoring) and hemodynamic changes as respiratory rate, heart rate, systolic blood pressure (SBP) and diastolic blood pressure (DBP) after IP instillation of the study drug. Results: In both groups, demographic profile were comparable and statistically insignificant. NRS scores was significant after a time interval of two hours postoperatively between the two groups , the difference remained up to 5 hours (p-value <0.05). In Group M, pain(NRS) score was significantly lower than the patients of ropivacaine 0.5% (Group R). The time of first rescue analgesia was statistically significantly longer in Group M(278±53.39 minutes)than Group R (216±49.03minutes)- (p value <0.0001). There was no statistically significant difference in haemodynamic parameters and mean respiratory Rate (p value >0.05)in the two groups. Conclusion: The findings of the study demonstrate that patients receiving the combination of morphine and ropivacaine experienced a notably lower pain scores and extended time to the first rescue analgesia. This suggests a synergistic interaction between morphine, an opioid analgesic and ropivacaine, a local anaesthetic, resulting in enhanced and prolonged postoperative analgesia.